ABR: Response to Crowding and Vegetation Shade in Impatiens capensis: Genetic Basis and Fitness Consequences

ABR：凤仙花对拥挤和植被遮荫的反应：遗传基础和适应性后果

• 批准号: 0129018
• 负责人: Johanna Schmitt
• 金额: $ 31.76万
• 依托单位: Brown University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-02-15 至 2006-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0129018&HistoricalAwards=false
• 关键词: ABR; Response; Crowding; Vegetation; Shade

Many plant species exhibit characteristic morphological and physiological responses to crowding and vegetation shade. This "shade avoidance" response is cued by a reduction in the ratio of red to far-red wavelengths (R:FR) in light transmitted through or reflected from green vegetation. This R:FR signal is perceived by light-sensing molecules known as phytochromes. Prior research from this project has demonstrated that phytochrome-mediated stem elongation increases lifetime reproduction of the native annual Impatiens capensis (jewelweed or touch-me-not) in dense stands, but plants induced to display the shade avoidance response at low density suffer reduced fitness relative to non-elongated plants. The present study will examine genetic variation among inbred lines in expression of shade avoidance traits across a range of densities, and assess the contribution of phytochrome-mediated developmental pathways to this variation. In addition, natural selection on shade avoidance traits will be measured in the field across a range of densities, in order to predict how shade avoidance responses will evolve in variable density environments. The results of this project will provide important information about the genetics and evolution of phytochrome-mediated shade avoidance responses in natural plant populations, and will provide an ecological and evolutionary context for current research on the molecular, genetic, developmental, and physiological mechanisms underlying plant responses to light. It will also help to inform selection strategies for crop improvement and provide an ecological context for recent proposals to increase yield by genetically engineering crops in which shade avoidance responses are blocked.

许多植物物种表现出对拥挤和植被阴影的特征形态和生理反应。这种“避免阴影”的响应是通过在通过绿色植被传播或反射的光中的红色与远红色波长（R：fr）的比率降低来提出的。该R：FR信号被称为植物色素的光感应分子所感知。 该项目的先前研究表明，植物色素介导的茎伸长增加了密集架上天然年度虫食的终生繁殖（Jewelweed或Touch-me-not），但植物诱使植物在低密度下显示出相对于非延长植物的低密度降低的避免遮阳剂。本研究将检查近交系的遗传变异在一系列密度范围内的阴影回避性状表达中，并评估植物色素介导的发育途径对这种变异的贡献。此外，在范围内，将在范围内测量避免阴影的自然选择，以预测在可变密度环境中避免阴影避免响应将如何发展。 该项目的结果将提供有关天然植物种群中植物色素介导的阴影回应反应的遗传学和进化的重要信息，并将为有关植物对光的植物反应的分子，遗传，发育和生理机制提供当前研究的生态和进化环境。 它还将有助于为作物改善的选择策略提供信息，并为最近的建议提供生态环境，以通过遗传工程作物来提高产量，从而阻止了阴影避免反应。